Solar energy

If you’ve ever used a magnifying glass to melt or burn something, you were using solar energy!

"Solar" is the Latin word for "sun" and it's a powerful source of energy. In fact, the sunlight that shines on the Earth in just one hour could meet world energy demand for an entire year!

We can use solar power in two different ways – as a heat source and as an energy source.

Nothing new under the sun

People have used the sun as a heat source for thousands of years. Families in ancient Greece built their homes to get the most sunlight during the cold winter months. In the 1830s, explorer John Herschel used a solar collector to cook food during an adventure in Africa.

Shedding new light on solar

Today, we can use solar collectors for heating water and air in our homes. If you've seen a house with big shiny panels on the roof, that family is using solar power.

We can also use solar energy to make electricity. The process is called photovoltaics. If you have a solar-powered watch or calculator, you're using photovoltaics!

In 1954, scientists at Bell Telephone discovered that silicon (an element found in sand) created an electric charge when it was exposed to lots of sunlight. Just a few years later, silicon chips were used to help power space satellites.

Why don't we use solar energy all the time?

Well, the biggest reason is that solar energy needs the sun, and the sun isn’t out 24 hours a day. However, as technology improves and costs go down, energy companies are installing more solar energy gardens to generate clean, renewable energy.

Alliant Energy operates Iowa’s largest solar garden. It’s located in Dubuque, Iowa. This site can generate up to five megawatts of direct current (DC) energy. Every year, it produces enough energy to power more than 700 homes.